FIG. 11 is a perspective view showing a conventional self-traveling manual wheelchair 50. The wheelchair 50 has such a configuration that wheels are mounted to a chair unit 60. The wheels include large drive wheels 51 mounted on the transverse sides of the chair unit 60, and small casters 52 mounted on both front corners. The drive wheel 51 has such a configuration that a tire 53 is fixed to a hub 55 with spokes 54, and that a hand rim 56 for transmitting a driving force by a hand of a user is mounted to the drive wheel 51. The chair unit 60 consists of a seat surface 61, a back rest 62, arm rests 63, leg supports 64, and a frame 65 for connecting them so as to form the chair unit. Further, on the rear side top parts of the frame 65, grips 65a used when a carrier pushes the wheelchair are mounted.
The drive wheel 51 is connected of the chair unit 60 by mounting a hub mounting part 57 fixed to the frame 65 to the hub 55. Further, the casters 52 are connected in such a manner that holding members 59b are mounted to axes 59a provided at the center of the casters 52, and the holding members 59b are fixed to the frame 65.
Although the configuration of the drive wheel 51 of a typically used wheelchair is that the tire 53 is fixed to the hub 55 with the spokes 54, as shown in FIG. 11 (conventional example 1), a drive wheel without a hub and spoken as recently been proposed. Specifically, as shown in FIG. 12 [A is a side view showing a wheelchair of a conventional example 2, B and C are perspective views thereof], a drive wheel 71 includes the tire 53, a rail part 72 mounted on the inner periphery thereof, and three pulleys 73 which are connected with the frame 65 of the wheelchair respectively. When the tire 53 rotates, the pulleys 73 travel on the rail part 72 in a state that the positions thereof are fixed with respect to the frame 65 (conventional example 2). (For example, see Japanese Patent Application Laid-Open Publication No. 2000-342632 (FIG. 1, FIG. 2, FIG. 5, and FIG. 6), Japanese Utility-Model Application Laid-Open Publication No. 62-66629, and Japanese Patent Application Laid-Open Publication No. 47-32550).
Further, metallic rings which are doubled inside and outside like a rolling bearing mounted via rollers are proposed as another example of a drive wheel without a hub and spokes (conventional example 3). For example, as shown in FIG. 13 [A shows a wheelchair of the conventional example 3, which is a partially broken perspective view of a drive wheel 81 thereof, and B is a sectional view taken along the line B-B shown in A.], a roller chain 75 compose a plurality of rollers 79 and links 76 to connect the rollers 79, and the roller chain 75 is provided between, and is so configured that an outer ring 78 mounted on the inner periphery of a tire 53 and an inner ring 77 mounted inside thereof and mounted to the frame 65 (see Japanese Patent Publication No. 2960161 (p. 4, FIG. 1 to FIG. 3) and U.S. Pat. No. 4,593,929 (FIG. 65, FIG. 66)).
In these conventional examples 2 and 3, there is no spoke 54, different from the conventional example 1. Therefore, when a baggage basket 70 is provided right under the seat surface 61 of a wheelchair, this provides an advantage that a baggage can be put into or taken out of the baggage basket 70 easily (see FIG. 12).